Asign onRollOver function to movie clip

is there any vay to assign functions to MCs after I load externel jpg
into them?
This is what I mean.

var mclListener:Object = new Object();
var thb_mcl = new MovieClipLoader();
function ld_mov1() {
for (i=1; i<=16; i++) {
thb_mcl.loadClip("./paintings/"+i+".jpg", “thb”+i+"_mc");
eval(“thb”+i+"_mc").onRollOver = function(){

well, this works fine before I load the JPGs.
is there any solution for this?